SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e283054c3fa6e6e0df3dedb1b807fbb739edaeff91ede1f803941d77c3865505' 
  AND token = 'tLPYzxhkA0uD0mhjnnhV7YO6nZbh1wfddiLdISrO8Qw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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