SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19eb4e9a1c997aed17b7fecd6259789870aa4411f842316299f66877bfeb2bee' 
  AND token = 'GsEA/o2OknXmY3oi1aK05qQxkqORfnJSJdGDjONz8C4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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