SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0638cc65bf4c535d6844fe9ba4322ac3dae82d1fb7f8ef15138cb3be13aca48a' 
  AND token = 'wYinoz/lkNCSN9kEWJvQmDQhjVDGL5+PlzGZY+B9i5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}