SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd27b26f6485424cd2d960d768ed523d5e1677ec7fb22826661ef1025465e6512' 
  AND token = 'UzIDy0pSgGH/RANG8J81mP8d/j43nbZXqZ/HTi3PF6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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