SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7150e28f5412739d7976416ea7954ee38697deb1e3717ba5ddeda40b048d577f' 
  AND token = 'WD+ZBVxnM0D2l9lhvRcmfHVUHeR62DkeuMz8QHNS72E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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