SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93fb66d0b315f2e0a207477ed403b153305d8d01c196c3bb00f40b1a9e63a93e' 
  AND token = 'TQPuSUwm5Bj5qx82g5+sGYYqdKxt+YMKFhpMV+VBmQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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