SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07fb584369c27e59fa02ab8553d33022bfc537236f88e4bdd00a9f2d187a2862' 
  AND token = '12zM8tGzIxkiRWAIwX4RAgx6+s0tVyXzjMGkLm5Qj98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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