SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ba79389b082ad50fcab454dd60a07640ae0a59d666fa322a464125f50f39527' 
  AND token = 'VfA56YPSUz3AEQuzvMYq5NN/P62/XJDlClDo8g/PIXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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