SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '975174ddbdc131c4efccccaa81de0883fef75d4dc46b1894177f4258d47318b1' 
  AND token = 'c15SQIT8KM7hp40793/EUrY6ctwbyv+xRNiPtuFgWus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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