SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c0b6b8b2b95f1a14d4e56d463a5487e44f1625c3cc25ceeb1bf567c93ad3e7e' 
  AND token = 'z/ux/rH7CDHWjqGu0VOMYWfl00IQxJwcpQqbfG5o+kg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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