SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a77c9e45ee484d9517800a38ee23843326c7a938c0d392d0f2506964901e7d7' 
  AND token = 'DwuxSYwgNxC2ShPsChUdABXt30WZVB6Lb/8TQH9Ggzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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