SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05f2a355660f0786ba2fcf9d6912e9275ca0812077a02fa478036e1b40ccd6d8' 
  AND token = 'D2wYSx8XiN8LfOjeMZBz441uggdYWUfBMhHma+765og=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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