SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'facccb1fad018bc6be695aaf13b9752e9cea538fce17d8b5b46fc859e5563d16' 
  AND token = 'FeRCZMKNtoq29Fyjzy9PyhSHxNOqhO0Lki/5ajv1d7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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