SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dab3c9b7084d77c1d78c7c113a6e570ec5bbe45e75e49f6216a649a1bdcd5862' 
  AND token = '+xvYf+i0G2FQKrDZ76zpjTjfJ8QD+unZFlkvC6mIOKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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