SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26bf203f6bcad47a15f7f2205a14251ab76eb03582e51e737daceb16891bfe3b' 
  AND token = 'AAJ8wGbXpqfnBE1sOC8BhJ5BhKaa8uLk7jvchH9kKpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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