SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a13e835f0b80dd0648def5ce61b2782fd5d9580cbe18cb4f59643576f427bc7' 
  AND token = 'pmmHyBLzZ1ISKJBjCNoZWmLSQR3hv0APeklKBam3umM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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