SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9a5079bfd6b2bb8590220a4d29d0f18fd9b4f95d7fe320b119702d0ff6124e6' 
  AND token = '68gz9eGXcEADA2+ZW1aeK+KrtPSNLnakM+E9r/KT7rs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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