SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ea676a0083f633f6886e14bbebb227249169e6a45a61ca9cb1e36f949e6e913' 
  AND token = 'Gf1C/vLT2ZymwFeV87/32Qt5QsKKgoUAxHMQZcYspdI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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