SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53c22aec3579e73d73938750f90e4246098d2e7bef51a370b89ee966fd14c82f' 
  AND token = '5uktCkVjmRqP2ITP/JfnwNHk1P+qm69hZX82SBSQPBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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