SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '692f09f2f5d54175921d9313c232da59d18d38bb28d592db952fc3a724bb25ac' 
  AND token = '7hAG03VIox2yFnly5xXFotqJCpPnaap6UTmN4SPz+/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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