SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5905b758520ef37b5786747b155664d2d0f7143e7077f8094cb87afe1f701477' 
  AND token = 'soXYyDYbkvq83c6Nqt2J2pjxlBaeCQ+p3Fi++DUri08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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