SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d5bdb14f55f2d03698121c2dd5a878003f5af0d78bbaef0630ffd5f3d8ed4a5' 
  AND token = 'W10udZ/oHilt3zB1+syeWSYvD/jAWcS7dT3j3WH7Xdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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