SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5eddbf3b107cf3122226be7ac2571c298339011e90e2f968d4f79af253318653' 
  AND token = 'ha9rggJlPJeRp8E688aqsqIXecC5dkMJsnXvC2H+LJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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