SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56f3310c5d40df10136c4b44126379207b18d6c67832443706b3cd7579b0957a' 
  AND token = 'h906HBXszEVG0pD5r2auOxqSWqZ4Iy4T9d5WBTqefDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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