SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ab8570889fa4a822542b00c1da2e9158a6ab96d5dbf5175625a751887cb3cdc' 
  AND token = 'CkbyNbkIgaEMSYmJh6uJor0SSlqmyWHEw4+ttYLfuoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}