SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d5e9ecb4f1d1c889c41cbef74d976443814dcca378510df66a73e715405286e' 
  AND token = 'fB7cdiPJbnKYxua9CY0BHtjCK3M0BbH1VPDQ0PMByRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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