SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53c486ace20c73a64d88f7c3de7a14feec12fa220a2d756ab535dc0626013506' 
  AND token = 'ekSSnMAWP+80+slRUFp/abjjrPQeyS4sxwYBZj+rxHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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