SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ce4a1c491d2f8b133450a5207fdc02c1c61ea66827011f648d7b55cfd5ca6ef' 
  AND token = 'er0XluM7pxlER0xuLBeSlyTJXkTEBbEpXFDixO14+j0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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