SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e38fac782c06ec806aa481d6e4042a0d94984748bf179edb5893236043a21deb' 
  AND token = 'ovaUdFkSnDymYrSulyuaE3BQYEiOfSfFuNedyJwq6F4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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