SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '57beae371734da0e59107fb962b28bc213c6b2caa49196ee0e4133e7c4dc17b7' 
  AND token = 'HLC1E82N1GT5rDU7GcVj/nnOb4mVO65czTbjL1GU69w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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