SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19b17403ea26ab354fd77c444a857f997eac5ff51fd33089594d026ff7f09063' 
  AND token = 'HFdFW6v+NFtRdZwaLrGDqfSQZWaGzR4eOT9Nq+b6EHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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