SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '962ba51ce4e70530a10f5e58cae085f0550878da48e369bf9422978d2042dce0' 
  AND token = 'gMOV2mQ6lYyFvDfXj/iCez1+FwyKXZTUxo7XBLo+350=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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