SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3722c8f0167de31626fb3a2e456dc461be25160c9fb4041a0bd9b88531f5e375' 
  AND token = 'kDhjHWarJ1PdCDeXvknfWyMs8q9jv3XFCBGghfxR8Yo=' 
  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"
    }
  }
}