SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd5a2f0d965501a7f0c50dff8ace985c9ab5a999a79045f4dbfb3b9360831a77' 
  AND token = 'kcV8LDKsJvDNhLq2kk3To9RXDOsY6P8WDFhHxz1Chpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}