SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c176bcb6cd7fe32c413ef4334b5bed6fa226d742df4cb83b975abf2d79d7f9b2' 
  AND token = 'nnJwUmiRW6hxaadxLFSKAsUoSqUkqwl1zggtT7uM3Hs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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