SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3c91d5a030d36df56bf168c6505063a4fac8d787a41dff119fc320881f94251' 
  AND token = 'QqflR+otla3w0Shpgb6bE/zklReZfoX1uW3S7b8UlFQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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