SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '203277bbcd68a31ab28169f8b262f9139fb946058d3aa4d41650862e30e04b7b' 
  AND token = 'E1eqkypHrd1VqFDEC/Zf8gPSK4lAkTyzczUHhZr6fhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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