SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c0130a95d4635453b397675f0893c56d372207375230e0b8d06c4558b722155' 
  AND token = '3gF65iuVYwNFh1vqMFo/ZBNj3oK6VFWcXqORbXJGdJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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