SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3e89991e185491c26ea5bda6263d2e37cc6b3133145a7397b73e7449875b344' 
  AND token = 'OTvIuALlD3wq4OyyPPZACcgOAvSZceYOr8r61vAMuns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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