SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe1403dd4f75342191ba5928a44797705cfcde961d6538ce4411edf7e8b069af' 
  AND token = '/qPmy5u1aTEq+vV44+JdBM0xBWmapFBusJR1pmbxOK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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