SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db664f9f2cf095e8b1c25a977b2f704adac2238b0c1126d0cf020058aa46c76a' 
  AND token = 'zN/tcDQPSuFj58WswfK5Fj8pPADtbP9cyNbubp2AIHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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