SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0b9428cbee4fdfdfce17ff8bb130c01e416813ff5c0011713d8aec72fde2eca' 
  AND token = 'h2gRIe1rSRcz92pEjkWbduRSITPTBcd3zlBSmyPABAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}