SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39541f74ffbb09ef7f17e980ac98d45935aa16bdaac9bcf50c00f4447a39efc7' 
  AND token = 'RTKpq544bNy+ntOAcpbDriYtvnSWJylZrc6iPgsqfTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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