SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74ffdfe8b5f546c2a977409027867ae96a6157003e9f2bb7237ae916628d4676' 
  AND token = 'mYPKhb/j+3gdOevO2O7LY3Kbevq6nOxvD5JR3AFQJhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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