SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0315e847a87d497c24f6e5ddf59fadd4dea1b142508dbb8e8c1fca67b75424e' 
  AND token = 'tyf4ZbUJn897svyLEFxTDcq3LrZWEoErxKXgPxov5gM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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