SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83dc58c55bc6a646a8472053eb5f061bd232c45f07684a5f317e5ee535a41f95' 
  AND token = 'NNOFfc6vIljkpbZP273DAZQqmhEnpLGoi+5rTYr9IP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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