SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccbe5e2cfe573c3ce23e87d2101d5a9fecd537f53982e19eb084ba701acb2992' 
  AND token = 'IQA96huIMgMvPQef7Xzgj+9562qSPBV9/KkJradT3no=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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