SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31fbca41874d6c57912067bb2772f240e16345ba3d22c2951ba21802bcd41ec7' 
  AND token = '+33RGeH4s1QPlxUiU5p9KlEw/9tbLbQ/vOmBC5CtdhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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