SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f09a59a9d6b0a1068f5b5a70d793d02ae0aa4381cc3a517f06a1f63d5730e50b' 
  AND token = 'On0xw9byD5Srr2avaFdVfOf4Om4JXSBgrnbuXe1Tm3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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