SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0f6f307940636e1dcd1aa1416fded70d163066fc299df85f7aadb305523adf4' 
  AND token = 'uA0SaJ0SvUhm6jD4BUwaiM9dTFhsKz1JxRLdf9mrCGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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