SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30915bf6612f6fe295e20935d77b550240906ef6bdf3ad328161bd70a5ebed01' 
  AND token = 'XyDqQqszOzSVzcZ+v/rGuyxeYp1gyehpVis2gEv9BXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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