SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6e865e718408bca2c6528631ed01187252027a466910a1ddf4e684b128cd7b8' 
  AND token = 'zGA2txnPIJWZ/ebhhhfU1likDyNkAKh6RbR2hfT3gJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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