SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '775bd2418b61a54e398b8fee406f10bf3b4415d22da48130c59d8051bbd2db34' 
  AND token = 'O+43CCQqyJxvBPqsKD0msrF/yuf6WNru9D/z1u8KjcE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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