SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2974c9e394349f3b8069fdb7b0eddeef65a62617571f54a4ada8c039aa692fd5' 
  AND token = '2kGuYxQY0mh6568kbArcEbxl/vi8UurtqYhxr/UoO10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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