SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe1f3198019201e6ec85b370248ecc94a3aff44ff6fafd7c2fa3252b0908b0a6' 
  AND token = 'p4OM5bEL/lgYgc+r69dW755S7L162FlH9vEVTPmtTpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}