SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e32a63eaeef77b43bb7c5adbc4436cb41d761ff305061c135c89a677ef7d96bd' 
  AND token = 'TR/Qz1bmj7VhqdAATXr5fOvhbZivUesYDGgUt/0A3kY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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