SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3c98b4766981aa35f17fc5d9ccb27f271bb9a6220e24925d3a3554567d0682c' 
  AND token = '2o4P1nNBPJSnAphX0KYSwwuA29x+tMMZeUSZS+69+24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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