SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba4256d87ff620bebe830479eb7ef4d6f758358f88c141158464e98cb12e96d5' 
  AND token = 'P86zBcqqiHS+SPdyRtozLqqPY0v3IjbmmhpqhQw7Nd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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