SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44ea6d2cbc2cfb80d9c3b0f3c3025240e90632a6fb6d847a171eea098cbe4c93' 
  AND token = 'ONAbzp7xPklB4j2HbjYsNgjCEDn2i2l7jxxFQ4IwOCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00062

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}