SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30a1d1b2d157533da18e45668bcf5b15b8c74151019e12fd691e1a83b7204441' 
  AND token = 'AlkAJV1GtLDUXS4z2dhoambSXGGwNn23zJ2iDP/7cKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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