SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '087fe091e4380e68521880fa10873c993f981782ccdfc06bc7e7b90ab63d2c36' 
  AND token = 'Jq7R5OcyxQjZiY5EygDoqAotAsNaZB6rHXPN+u2dw94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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