SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b6a229a8e229b2e661d7a5940b5efad8b5abbf68139436ba77c006971912a6c' 
  AND token = 'RCeQTcrXthzk/NjBbJwTDXpAY4NFrJP96kgRFyGR5bM=' 
  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"
    }
  }
}