SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baf71d0bed433151939b6be2900b62f0c97a0b4191f8d05836ea6a6508c0d4b5' 
  AND token = 'Z5E4JVKDJJadgow1HTzsXiS2XOzD3UYvYvcLdjL7enY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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